399 research outputs found
Aplicación de nuevas tecnologías para la impartición del curso cero en la ETSI Agrónomos
En los últimos años, muchos estudiantes de Ingeniería acceden a la Universidad con numerosas lagunas en los conocimientos básicos de Física y en el manejo de las herramientas matemáticas, por lo que terminan abandonando sus estudios el primer año. Para disminuir la tasa de alumnos que abandonan sus estudios, en la Universidad Politécnica de Madrid se están desarrollando Cursos Cero cuyo objetivo es dotar a los alumnos de la base necesaria para abordar con éxito su primer año en la Universidad. Por otra parte, con el fin de adecuar las enseñanzas al Espacio Europeo de Educación Superior, y promover el aprendizaje autónomo del alumno, el grupo de Innovación educativa GIE-44 de la Universidad Politécnica de Madrid hemos complementado el Curso Cero que se imparte de forma tradicional con una plataforma virtual del curso que presenta la asignatura en una forma más atractiva mediante el uso combinado de la metodología tradicional de enseñanza con las metodologías interactivas que impliquen al alumno en el proceso de aprendizaje de forma autónoma
Germination of grass seeds subjected to stationary magnetic field
The objective of the present study is to determine and quantify the effect produced by a stationary magnetic field in germination of patrense seeds (Festuca arundinacea and Medicago sativa, L). Seeds were exposed to 250 mT during different periods of time: 10 minutes, 20 minutes, 1 hour, 24 hours or in a chronic way, doses (B1-B5). Parameters used were average germination time (AGT) and the necessary time for germination of 1, 10, 25, 50 and 75% of seeds (T1 - T7S). According to results obtained with alfalfa seeds, it can be said that the AGT is significant less in seeds exposed to the magnetic field (20,40 hr for B5, 20,88 for B4, 21,36 for B2 vs 25.68 hr for the control group). Control T was 30,24 h while in treated seeds it was significant less: 22,32 hr, 23,76 hr, 24,48 hr, 24,72 hr, and 24,96 h for the B5-B1 dose respectively. For festuca a reduction in AGT for treated seeds can be observed in comparison to the control group. T25 for the control group was 50,16 hr while for treated seeds it was 48,00h for B4 and 47,28 hr for B5. The rest of the parameters evaluated were also less. In consequence, the reduction in the parameters evaluated implies that the germination speed is greater. - El objetivo de este estudio es determinar y cuantificar el efecto de un campo magnético estacionario en la germinación de semillas pratenses (Festuca arundinacea Sch. y Medicago sativa L.). Las semillas fueron expuestas a 250 mT durante distintos periodos de tiempo: 10 minutos, 20 minutos, 1 hora, 24 horas ó de forma crónica, dosis (B1-B5). Los parámetros utilizados fueron: tiempo medio de germinación (TMG) y el tiempo necesario para que germine el 1, 10, 25, 50 y 75% de semillas (T1-T75) proporcionados por Seed-calculator software. De los resultados obtenidos con semillas de alfalfa se desprende que el TMG fue significativamente menor en las semillas expuestas a campo magnético (20.40 h para B5, 20.88 h para B4, 21.36 h para B2 vs. 25.68 h para el control). El T75 del control fue 30.24 h mientras que en las semillas tratadas fue significativamente menor: 22.32 h, 23.76 h, 24.48 h, 24.72 h y 24.96 h para las dosis B5 - B1 respectivamente. En festuca destaca la reducción del TMG obtenido para las semillas tratadas frente al control. El T25 del grupo control fue 50.16 h mientras que para las semillas tratadas se obtuvo 48.00 h, para B4 y 47.28 h para B5. Los demás parámetros evaluados también resultaron menores. En consecuencia, la reducción en los parámetros evaluados implica que la velocidad de germinación es mayor
Using interactive methods for teaching principal axes and moments of inertia
Engineering analysis and design often uses properties of plane sections in calculations. For example, in stress analysis of a beam under bending and torsional loads, you use the cross-sectional properties to determine the stress and displacement distributions in the beam cross section. In calculating the natural frequencies and shapes of a machine part, you also need to know the area, centroid, and various moments and products of inertia of a cross section or a composed cross section. The centroid, moments and products of inertia of an area made up of several common shapes (rectangles usually), may thus be obtained by adding the moments of inertia of the component areas. However the parallel-axes theorems should be used to transfer each moment of inertia to the desired axis. This procedure is used to calculate the second moments of structural shapes (U-shape, L-shape, C-shape,…) because the determination of their moments of inertia is necessary for design structural members. Many engineering students are introduced to the ideas and concepts of Mohr’s Circle when studying stress states due to various loading conditions on structures or machines. Mohr’s circle provides a visual representation of what is happening, and the positioning of the stress states on an element relative to a set of coordinate axes. In this paper we propose the use of interactive methods for teaching this part of Mechanics. A set of simulations designed with the Modellus 2.5 software are used for calculating centroids, moment and product of inertia and their properties. Mohr´s circles are also drawn with interactive simulations to obtain the principal axes and moments of inertia of structural shapes. For solving problems, students can interact in the simulation, by changing shapes, size, angles, etc
Uso de simulaciones interactivas para el cálculo de momentos y direcciones principales de inercia
Los denominados momentos y productos de inercia, son magnitudes que aparecen con frecuencia en los problemas de ingeniería, por ejemplo en el estudio de fuerzas distribuidas y en el cálculo de deflexiones de vigas. El segundo momento de área, también denominado momento de inercia de área, es una propiedad geométrica de la sección transversal de elementos estructurales; está relacionado con las tensiones y deformaciones máximas que aparecen por flexión en un elemento estructural y determina la resistencia máxima de un elemento estructural bajo flexión; por ello es importante determinar la orientación del elemento en la que la resistencia es máxima. En ocasiones dichas elementos estructurales planos se pueden descomponer en varias secciones planas (normalmente rectángulos), como en el caso de vigas cuyos perfiles adoptan forma de U, L, C, T,…etc, En este trabajo se propone el uso de simulaciones interactivas realizadas con el software libre Modellus 2.5, para el estudio de las propiedades y teoremas de segundos momentos de un rectángulo, por ser el elemento predominante en las secciones compuestas, pudiendo el alumno modificar sus dimensiones y posición. Mediante una simulación se puede calcular la posición del centroide de figuras compuestas, los segundos momentos respecto a diferentes ejes y posteriormente determinar los momentos y direcciones principales de inercia mediante el círculo de Mohr y el método de los multiplicadores de Lagrange
Effect of Static Magnetic Field Exposure of Salvia Seeds on Germination Characteristics (Salvia officinalis, L.)
The main objective of this study is to determine the effects of magnetic treatment, in addition to the geomagnetic field, on germination of salvia officinalis L. seeds. This objective has a practice application in agriculture science: to obtain an early growth of salvia. A great development of crops of medicinal, condimentary and aromatic plants crops is taking place in Mediterranean countries due to their high added value as consequence of the Fitotherapy reappearance among other reasons. In recent decades magnetic treatment of seeds became very popular in agricultural sector. Salvia seeds were exposed to 125 mT stationary magnetic field generated by magnets for different time: 10 minutes (A1), 20 minutes (A2), 1hour (A3), 24 hours (A4) and chronic exposure (A5). Other group of seeds were subjected to a magnetic pretreatment (P1). Not exposed seeds were used as control (C). Germination tests were performed at temperature 20-22ºC under laboratory conditions. The selected germination parameters were: time for the first seed to germinate (T1), time to reach 10, 25% etc. germination (T10, T25, T50 and T75), number of germinated seeds (Gmax) and the mean germination time (MGT), all of them were provided by the Seedcalculator software package. Results indicate that magnetic field application enhanced the seed performance in terms of laboratory germination, rate and percentage of germination compared to unexposed (C). The germination parameters recorded for salvia seeds and for each treatment and pretreatment were lower than corresponding control value. Among the various treatments, chronic exposure to 125mT (A5) gave best results. Data obtained for salvia treated seeds showed that MGT was significantly reduced compared to control ones (79.68 h for A3, 81.84 h for A4, 75.60 h for A5, and 81.60 h for P1 vs. 95.28 h for control). Parameters (T1-T50) and MGT were also significantly reduced for treatments A2, A3, A4, A5 and P1
Tratamiento magnético como técnica estimulante de la germinación de semillas de soja
El campo magnético está presente en la naturaleza y afecta al reino vegetal y animal. El bioelectromagnetismo es el estudio de los efectos de los campos electromagnéticos sobre los sistemas biológicos y sus interacciones con los campos magnéticos naturales y artificiales. Estudios previos han determinado que la aplicación de campos magnéticos modifica la velocidad de germinación y el desarrollo de plantas. La soja constituye uno de los cultivos oleaginosos más importantes del mundo: en las últimas décadas su popularidad se ha incrementado por considerar esta leguminosa como una fuente de salud. Este estudio se centra en el efecto que se puede producir en la germinación de la soja (Glycine max L.) al exponerlo a campos magnéticos estacionarios de 125 mT, 250 mT y 300 mT durante diferentes tiempos de exposición (10¿,20¿, 1 hora, 24 horas y de forma permanente). Se observan diferencias muy significativas tanto en la velocidad de germinación como en el porcentaje de semillas germinadas entre las semillas control y las tratadas. Estos resultados ofrecen nuevas posibilidades para una más efectiva producción vegetal
Germination of grass seeds with recycling waste water
This study was designed to determine the effects of residual water irrigation on the rate and percentage of germination of grass seeds. Germination tests were carried out to compare the seeds irrigated with recycling waste water with seeds irrigated with distilled water. Test with Festuca arundinacea Sch. and Agrostis tenuis L. seeds was performed under laboratory conditions. Parameters used to evaluate germination were: number of germinated seeds (Gmax), mean germination time (MGT), the time required for 1 to 75%, of the seeds to germinate (T1, T10, T25, T50 and T75). The evaluated parameters for both seeds irrigated with recycled waste water were below the control seeds parameters. These reductions involve that germination rate was increased. Recycling waste water could be used for irrigation of grass seeds because produces a beneficial effect in germination rate and percentage
Multidisciplinary exercises: coordination practices and applications from fundamental to applied subjects in agriculture engineering
This activity is carried out in the framework of an innovation project, whose main objective is to coordinate mathematical, physical and engineering contents for a transversal educational path focused on mechatronics, automated control and information and communication technologies. In such sense one important task in this project is the elaboration of practices and joint applications which will be proposed to the students in successive matters upon different points of view: “Common Practices”. Through this activity students will be guided to establish relationships between their scientific basic training and their technological formation. The students will work on the same example during different academic years and semesters using common materials and working spaces. The whole experience will be displayed in Moodle, a virtual learning environment. A preliminary proposal of “Common practice” is presented in this paper as one example: “Design and Analysis of Suspensions Systems for Stabilizing the Roll of Spray Booms”. In this example students of different academic levels are asked to solve the complexity of the problem along different subjects: Field measurements (analysis of variability on chemical applications using a spray boom) will be realized in the Agriculture Machinery topic - equivalent to 4.5 ECTS -. Analytical models for the analysis of different suspension systems in the Mechanics and Mechanisms topic -4.5 ECTS -. In Agriculture Applied Electronics – 2.5 ECTS – sensors and actuators will be studied to design controllers. Control strategies for damping the resonance frequency of the suspension will be studied in Process Simulation and Optimization – 3.5 ECTS –. And, finally, the design and development of a vehicle with a spray bar and the corresponding suspension systems will be done in the Robotics topic – 7 ECTS –
Implementación de un sistema b-learning en la enseñanza práctica de Fisiopatología
Fac. de FarmaciaFALSEsubmitte
Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2
The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
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